Purpose: In patients with a high life expectancy at the time of surgery for colorectal cancer (CRC), the long-term outcome may be influenced by factors other than their cancer. We aimed to investigate the long-term outcome and cause of death beyond a 5-year surveillance programme.
Methods: We evaluated the overall survival (OS) and cancer-specific survival (CSS) of a population-based cohort of stage I-III CRC patients <75 years old who completed a systematic surveillance programme.
Results: In total, 161 patients <75 years old, 111 (69 %) of whom were node negative (pN0), were included. The median follow-up time was 12.1 years. The OS was 54 % at 15 years and differed significantly between the pN0 and pN+ patients (65 vs. 30 %; P < 0.001); CSS (72 %) also differed between the pN0 and pN+ patients (85 vs. 44 %; P < 0.001). For the 5-year survivors (n = 119), 14 (12 %) died of CRC during additional long-term follow-up (7 each for pN0 and pN+), and 6 patients (5 %; all pN0) died of other cancers. Patients aged <65 years exhibited better long-term survival (81 %), but most of the deaths were due to CRC (10/12 deaths). Only two of the 14 cancer-related deaths involved microsatellite instable (MSI) CRC. Females exhibited better OS and CSS beyond 5 years of surveillance.
Conclusions: The long-term survival beyond 5-year survivorship for stage I-III CRC is very good. Nonetheless, cancer-related deaths are encountered in one-third of patients and occur most frequently in patients who are <65 years old at disease onset-pointing to a still persistent risk several years after surgery.